Dammit, this ALMOST Worked.1) Save your project
2) Save another copy using "Save As..." - you wont need the preview files.
3) Close Premiere
4) Go to the folder where you have all your avi clips and make a new subfolder called 'hidden'. Move all your avi clips into there.
5) Open up the duplicate copy of your project. It will then stop when it can't find an avi file. When it asks you to locate the avi file, instead point to the original avs version. This should load up your project with nice high quality DVD footage. If AVIsynth crashes at any point on the timeline, then make sure you haven't slowed down any of the footage too much or used too many effects on a clip.
Indeed, it DID switch to avisynth footage, and it was the same 'clip' in the same spot in my project time line. The clip had exactly the same duration. The difference? The 37 seconds of avisynth footage was the FIRST 37 seconds (not the 37 seconds I wanted). I followed these directions to the letter. I tried it several times tweaking a few things, but kept getting the same problem.